<p><strong>Fig. 3.20.</strong> Differences in sea level height across the world ocean can be measured using NASA satellites. The red colors are areas of higher sea level, the dark blue areas indicate the lowest sea level height.</p>

Fig. 3.20. Differences in sea level height across the world ocean can be measured using NASA satellites. The red colors are areas of higher sea level, the dark blue areas indicate the lowest sea level height.

Image courtesy of National Aeronautics and Space Administration (NASA)